U.S. Sen. Jack Reed is getting some backup from two of his fellow Southern New England Democrats as he battles to change a bipartisan compromise on student-loan rates.

U.S. Sens. Elizabeth Warren and Sheldon Whitehouse on Tuesday sent email blasts to their campaign supporters in a bid to rally support for Reed, who is seeking to amend the loan legislation to cap students’ interest rates at 6.8%, lower than the 8.25% currently envisioned. The bill could be voted on as soon as today.

“Senator Jack Reed’s amendment is the only plan on the table right now that guarantees student loan interest rates won’t skyrocket above their current levels,” Warren wrote in an email pushing subscribers to sign up on Reed’s website in support. “We need to pass this amendment for our kids and grandkids.” The subject line of Warren’s email said: “The whole system stinks.”

“Unfortunately, our opponents would rather profit off our students than invest in them – so Jack is going to need all of us to stand with him to win this fight,” Whitehouse wrote in his email. “I’ve joined a group of Senators to work to pass Senator Reed’s amendment. But we need your help before this week’s vote.”

The emails are another sign of the increasing closeness of the Rhode Island and Massachusetts U.S. Senate delegations now that Warren and the newly elected Ed Markey have joined Reed and Whitehouse in Washington. All four are down-the-line liberals, and they share many of the same policy passions, notably financial regulation for Reed and Warren and climate change for Whitehouse and Markey.